Door interlock



June 9, 1964 J. B. MAHER ETAL DOOR INTERLOCK 2 Sheets-Shae Filed Nov. 1, 1960 A null June 9, 1964 J. B. MAHER ETAL DOOR INTERLOCK 2 Sheets-Sheet 2 Filed Nov. 1, 1960 United States Patent Ofiice 7, 3,136,007 Patented June 9, 1964 3,136,007 DOOR INTERLOCK James B. Maher, Chicago, 111., and John A. Follett, Hammond, Ind., assignors to Chicago Bridge 8: Iron Company, Chicago, Iil.

Filed Nov. 1, 1960, Ser. No. 66,482 11 (Ilaims. (Cl. 20-16) This invention relates to an interlock system for controlling the alternating angular displacements of opposed rotatable structures. It is more specifically concerned with an interlocksystem for use in controlling the operation of doors or similar closures enclosing the opposed ends of lock systems which penetrate a partition separating a first environment from another environment having different environmental conditions than the first.

1n installations such as tunnel excavation, caissons, industrial processing equipment, autoclaves, vulcanizers, ovens, research testing chambers, environmental chambers and other such systems where it is necessary to provide convenient access for personnel and equipment without destroying the fluid-tight integrity of the system, conventional lock chambers are employed to connect the interior of the installation with an outer atmosphere. The locks are chambers which traverse a partition wall separating the exterior atmosphere from the interior atmosphere and which are enclosed by means of suitable fluidtight doors. In order to avoid or minimize a loss of pressure in the interior atmosphere, which can be either sub-atmospheric or super-atmospheric with respect to the exterior atmosphere, it is important to control the operation of the lock doors so as to permit the operation of only one closure at a time. In order to effect this objective, interlock systems have been devised for controlling the operation of the air lock closures.

In accordance with this invention, there is provided a simple air lock system which can be operated independently or coordinated with equipment used for the operation of the door closing and opening.

The interlock of this invention provides a positive, mechanical interlocking device whereby operational safety of a high degree is maintained.

In the drawings:

FIGURE 1 is an isometric view of an air lock employing the interlock system of this invention with a portion of the air lock walls being cut away; I

FIGURE 2 is a fragmentary cross-sectional view illustrating the mounting of the locking ring on the tubular end wall ofthe lock and its relationship with the door closure;

FIGURE 3 is a fragmentary plan view of an illustrative embodiment of the interlock system taken along line 3-3 of FIGURE 1;

FIGURE 4 is a fragmentary cross-sectional view taken in elevation illustrating the interlock system shown in FIGURE 3;

FIGURE 5 is an enlarged cross-sectional view of a pressure sensing control employed as a means for controlling the power system for operation of the door;

FIGURE 6 is a fragmentary end view taken along line 66 of FIGURE 3, illustrating the relationship of the interlock latch system when the closure door is in the unlocked position;

FIGURE 7 is a fragmentary end view taken along line 77 of FIGURE 3, showing the relationship of the interlock latch system when the door is in the locked position; and

FIGURE 8 is a view of the control panel for use with the operating handle located within the air lock.

Referring to the drawings, in FIGURE 1 there is shown an air lock containment vessel the walls 10 of which are W shown in fragmentary form. The air lock comprises a tubular chamber 11 penetrating the sidewall 10 of the vessel. The air lock as illustrated comprises a tubular chamber 11 which is 16 feet long with an inside diameter of 11 feet 6 inches installed in sidewall 10 employing a reinforcing ring 12 in accordance with United States Patent No. 2,869,749. To each end of the tubular chamber 11 is welded or otherwise attached a tubular end wall 13 of greater thickness than the sidewall of tubular chamber 11. The end wall 13 extends outwardly from the end of the tubular chamber 11. End wall 13 is provided with a peripherally mounted lip flange 14 which serves as a retaining ring for the locking ring 15 by engaging one side of locking ring 15 which is rotatably mounted on tubular end 13. To facilitate the rotation of locking ring 15, bearing wheels 16 fitted in brackets 17, are mounted on the flange member of stiffener ring 18 attached to end wall 13 adjacent the terminal end of tubular chamber 11.

Each end of the airlock is fitted with a closure assembly for hanging and operating a door closure 19. Each assembly comprises a pair of brackets 20 and 20' attached to the flange member of stiffener ring 18 to provide journals for hinge pin 21 which is mounted in the opposed brackets joined to the terminal flange or stiflening flange 18. A pair of spaced lateral arms 22 and 22 are aflixed at one end to hinge pin 21 and at the other end to door closure 19, thereby permitting the rotation of door closure 19 about the longitudinal axis of hinge pin 21. t

Peripherally spaced on the side flange 24 of door 19 are a plurality of spaced cam bars 25. Similarly, locking ring 15 is fitted with cooperating spaced cams 26 provided with wedge-shaped cams which upon rotation of the locking ring 15 engage with the cam surfaces of cams 25 to bring door closure 19 into fluid-tight relationship with the end wall 13. The door-closure is provided with a peripheral head 28 which engages with a suitable gasket 29 fitted in end wall 13 in order to insure the maintaining of a fluid-tight relationship within the air lock when the door closure is closed.

The opening and closing of closure door 19 is controlled by means of a door swing mechanism illustrated at 30. The mechanism consists of a hydraulic cylinder 31 which is connected by means of a crankarm, rack and pinion, or other motion translation linkages, not shown, to hinge'pin 21. A handrail 32 is secured to the inner face of the closure door 19 to permit any manual assistance which may be necessary for opening and closing the door 19. i

The rotation of locking ring 15 is effected by any suitable mechanism, such as a chain drive, rack and pinion hydraulic system 33 as illustrated in FIGURE 1, or other similar mechanisms for effecting the rotation. The illus trated hydraulic arrangement consists of a hydraulic cylinder 35 pivotaily mounted by means of a stationary bracket 36 to stiffener flange 18. The piston arm 37 of hydraulic cylinder 35 is pivotally connected to a similar bracket 38 secured to the web element of the locking ring. Hydraulic control'line 39 and 39a control the flow of hydraulic fluid to the hydraulic cylinder from a power pack not shown. The control of the hydraulic system is provided by means of a push-button station S suitably located within the air lock as well as outside the air lock adjacent each of the air lock closures. By proper manipulation of the push-buttons in cooperation with the interlock system of this invention, the hydraulic system effects the rotation of the locking rings 15 as well as the operation of the door-swing mechanism 30.

A specific illustrative embodiment of the interlocking system of this invention as shown in FIGURES 3 and 4 comprises a pair of reciprocatively mounted latch pins 40 and 41. One end of latch pins 40 and 41 is journalled in the web element of stiffener ring 18 as well as in gear housing 43 and 44. A cooperating fixed latch bracket 45 and 46 secured to the flange element of stifiener 18 is provided with latch apertures 47 and 48 which cooperate with the latch pins 40 and 41. Latch apertures 47 and 48 are in axial alignment with the axis of reciprocative movement of latch pins 40 and 41. The reciprocative movement is provided by means of a rack 49 and t) and pinion 51 and 52 arrangement which is located within gear boxes 43 and 44. Pinions 51 and 52 are mounted on transverse axles 53 and 54 traversing gear boxes 43 and 44. The gear boxes 44 and 45 are located on the exterior wall of the tubular chamber with one gear box 43 being mounted adjacent the interior door assembly and the other gear box 44 being mounted adjacent the exterior door assembly. Transverse axles 53 and 54 extend beyond the sides of gear box 44 and 45. One end of transverse axles 53 and 54 penetrates the sidewall of tubular chamber 11 through suitable fluid-tight packing glands 55 and 56 to provide interlock control means within the tubular chamber 11 as well as outside of the tubular chamber. Suitable operating handles 57 and 58 installed on the interior end of the operating shaft and handles 59 and 60 installed on the exterior end of the operating shaft are used to control the movement of the latch pins 40 and 41. The cooperating alternating movement of latch pins 40 and 41 is provided by the angular displacement of the operating handles 57 and 58 and interlock link 61 which is pivotally connected to the cooperating terminal ends of operating handles 57 and 58.

A pressure equalizing system is controlled by pressure valves 62 and 63. One outlet of the valves 62 and 63 is open to the atmosphere exterior to the tubular chamber 11 whereas the other outlet is connected to the interior of tubular chamber 11 by means of a suitable fitting in order to permit the pressure within the air lock to equalize with pressure in the atmosphere to which the interior of the air lock will be exposed upon opening the selected door 19. The coordinated operation of the pressure equalizing valves 62 and 63 is provided by means of latch pins 40 and 41. It will be noted that the valve stems 64 and 65 of the pressure equalizing valves 62 and 63 are controlled by lever arms 66 and 67 pivoted at one end to the body valves 62 and 63. The other end of the levers are provided with cam followers 68 and 69. Cam followers 68 and 69 are engageable by the cammed surfaces 70 and 71 provided at the end of the latch pins 40 and 41. Upon engagement with the cammed surface of the reciprocatively moving cooperating cam the follower of the appropriate valve stem is actuated and the desired pressure equalizing valve is opened. Upon disengagement of the cammed surface of the latch pin with the cam follower, the spring loaded valve stem returns the equalizing valve to the normally closed position to await the next cycle of operations.

To effect the operation of the interlock system of this invention locking ring 15 is provided with a movable latch plate 73 which is mounted in a laterally extending position from the web element of locking ring 15 thereby moving in angular displacement with the rotation of the locking ring. An aperture 74 is provided in latch plate 73. The latch plate 73 is positioned on the locking ring 15 to move between the web of stiffener ring 18 and fixed latch bracket 45 which permits the latch aperture 74 of the latch plate 73 to be brought in or out of alignment, as the case may be, with the longitudinal axis of the latch pins 40 and 41 and the aperture 47 in latch bracket 45.

In operating the interlock device of this invention, it will be noted that movement of the operating handles 57--59 or 58-60 controls the positioning of the latch pins 40 and 41. In FIGURE 1, the interlock assembly of this invention is shown with the interior door in the fully closed and locked position and the inside equalizing valve 63 completely closed. The outside door and equalizing valve 62 are completely open. Upon closing the outside door and rotating the locking ring 15 from the unlocked position as shown to the locked position, the apertures in the latch plate and the fixed latch bracket are moved into an aligned position. With apertures in alignment, the latch pin 40 is now in a position to slide through the aligned apertures to lock the door assembly in the closed position. To open the inside door, either interior operating handle 57 or 58 is rotated counter-clockwise from position 1 through position 3 as shown in FIGURE 8. In travelling from position 1 to position 2, the locking pin 4!) travels through a distance such that at this intermediate position the locking pins 40 and 41 engage both of the locking rings. With this pin arrangement on the outside door, the equalizing valve 62 has been disengaged and allowed to fully close. The locking pin 40 on the outside door has passed through the latch plate aperture '74 of the outside door assembly and extends into the aperture 47 of the fixed latch bracket 45 thus holding the outside lock ringin the locked position. On the inside door assembly latch pin 41 has engaged equalizing valve cam follower 69 and fully closed the valve. However, the fixed latch aperture bracket and latch plate on the outside door are still engaged and the inside locking ring cannot yet be rotated from the locked position.

As described, the rotation of the inside door operating handle from position 1 to an intermediate position 2 will lock the outside door, close the outside equalizing valve and open the inside equalizing valve in this sequence. Further rotation of the operating handle from position 2 to position 3 will disengage the locking pin 41 on the inside door and the fixed latch bracket on the inside door assembly from the initial position.

Accordingly, latch pin 41 will have then withdrawn from both the fixed latch brackets and the rotatable latch plate and the inside door locking ring can now be rotated from the locked position and the door swung open. Latch pin 40 associated with the operation of the outside door is also moved a distance from its initial position and extends through the fixed latch bracket on the outer door assembly.

An additional safety device as shown in FIGURE 5 is provided by means of the pressure sensing control installed in the wall of tubular chamber 11. This pressure sensing device is interlocked with the electrical system by means of limit switches 81 and 82 located within housing 79 which hold the hydraulic system controlling the movement of the door opening mechanism and locking rings inoperable until the pressure inside the lock is equalized with that outside the door which is selected to be open. It will be noted that the pressure sensing device 80 comprises a chamber 83 having a flexible diaphragm 84 or the like mounted therein. One side of the diaphragm is in communication with the interior of the tubular chamber 11 through line 85. The other side of the diaphragm is connected by means of a push rod 86 to a lateral trip arm 87 which controls the operation of limit switches 81 and 82. Electrical leads, not shown, connect the switches to the power pack. While such a device is preferred from a safety standpoint, the noise caused by the air rushing through the pressure equalizing valves is evidence to the pressure door operator that the pressure outside the air lock had not yet equalized with the pressure inside the air lock. It is essential that the pressure he equalized before opening the door because an unequal pressure on the door could result in serious injury to the operator as the air pressure within the air lock might blow the door open and forcibly remove it from its mounting. Thus, the interlock structure should be controlled as shown for it will prevent or minimize equal pressure on the doors.

'Again referring to FIGURE 8, in normal operation, the operating handle 57 or 58, shown in phantom view, will only be rotated from position 1 through 3, or 3 through 1. Position 4 shown in FIGURE 8 is a door in use indicator. By manually lifting a spring loaded catch 90, the operating handle may be further rotated to position 4. The indicator card of the operating handle boX will give visual indication to a remote operator that the opposite door is not only in use, but also should not be operated until the user has cleared certain slow moving equipment or personnel through the door.

The spring loaded catch 90 is located at each handle inside the lock. When the door in use position of the operating arm is reached, a limit switch 91 will be actuated and a warning light of suitable color located at the push-button station outside of the locks will be lighted. The light will be an indication that the door is in use, and remote control should not be attempted. The hydraulic system cannot be operated. The light will be additional to another warning light which indicates the door is open. It is not necessary to move the operating handle to position 4 for normal operation of the door. The door in use indicator can be set from inside the lock only.

In the illustrative air lock a floor 92 is shown. If desired, drop bridges can be provided for the locks which will operate automatically to bridge any gap between floor structures and the air lock floor. The bridge movement will be operated by a limit switch actuated by the door swing. When a door is closed, the bridge will be in the upright position, degrees past vertical. Bridge rate of descent is controlled by the hydraulic system with flow control valves.

Although the illustrative lock door has electrical or hydraulic control, door operation as controlled by the interlock system of this invention can be manually 0perated and mechanically interlocked. It can be operated from all positions specified.

Although the foregoing invention has been described with reference to the foregoing specific embodiment, it is apparent to those skilled in the art that it has other applications, as well as variations and modifications within the scope of the invention. Conventional materials of construction are used in fabricating the structure of, this invention and the selection will depend upon the design requirements.

What is claimed is:

1. An interlock system for controlling the alternating angular displacement of a pair of opposed rotatable doorlocking means having a latch aperture provided in each of said locking means, said system comprising a framework, an interlock latch mechanism mounted on said framework, and including a first latch pin cooperating with one of said locking means, a secondreciprocating latch pin journalled on said framework and cooperating with the other of said locking means, a pair of fixed latch brackets mounted on 'said framework, each bracket being provided with an aperture, the aperture on one bracket being aligned with the longitudinal axis of said first pin and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, means for interconnecting said latch pins in out-of-phase relationship with the respective locking means with which said pins cooperate to alternately latch one of said locking means when the other unlatched locking means is in a rotatable condition, and means for reciprocatively moving said pins in unison.

2. An interlock system for controlling the alternating angular displacement of a pair of opposed rotatable doorlocking means each having a latch plate mounted thereon having a latch aperture provided in each of said plates; said system comprising a framework, an interlock latch mechanism mounted on said framework and including a first reciprocating latch pin journalled on said framework cooperating with one of said locking means, a second reciprocating latch pin journalled on said framework cooperating with the other of said locking means, a pair of fixed latch brackets mounted on said framework and spaced therefrom, each bracket being provided with an aperture, the aperture on one bracket being aligned with the longitudinal axis of said first pin and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, the apertures on said latch plates being adapted to be rotated in alignment with the longitudinal axes of said pins, means for interconnecting said latch pins in out-of-phase relationship with the respective apertures in said bracket and latch plate with which said pins cooperate to alternately latch one of said locking means when the other unlatched locking means is in a rotatable condition, and means for reciprocatively moving said pins in unison.

3. In an interlock system in accordance with claim 2 in which said latch plate is rotatable into'a position between said framework and said bracket.

4. An interlock system for controlling the alternating angular displacement of a pair of opposed rotatable doorlocking means each having a latch plate mounted thereon having a latch aperture provided in each of said plates, said system comprising a framework, an interlock latch mechanism mounted on said framework and including a first reciprocating latch pin journaled on said framework cooperating with one of said locking means, a second reciprocating latch pin journalled on said framework cooperating with the other of said locking means, a pair of fixed latch brackets mounted on said framework and spaced therefrom, each bracket being provided with an aperture, the aperture on one bracket being aligned with the longitudinal axis of said first pin and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, the apertures on said latch plates being adapted to be rotated in alignment with the longitudinal axes of said pins, means for interconnecting said latch pins in out-of-phase relationship with the respective apertures in said bracket and latch plate with which said pins cooperate to alternately latch one of said locking means when the other unlatched lockingmeans is in a rotatable condition, means for reciprocatively moving said pins in unison comprising a rack mounted on each of said latch pins, a pinion gear journalled on said framework engaging each of said racks, and a lever means for rotating said pinion gears.

5. In an interlock system in accordance with claim 4 in which said means for interconnecting said latch pins in out-of-phase relationship cooperates with said lever means. l

6. In an intermediate airlock interconnecting an exterior atmosphere and an interior atmosphere separated by a partition wall which comprises a tubular chamber penetrating said partition wall, the respective ends of said chamber being enclosed by an exterior pressure door assembly and an interior pressure door assembly, said assembly including a door hinged to said chamber, a locking ring encompassing said doors and rotatably mounted on the opposed ends on said tubular chamber, each of said locking rings having spaced cam surfaces constructed to rotatably engage corresponding cam surfaces on said door to provide a fluid-tight seal between said door and said chamber and having a latch plate mounted thereon with a latch aperture provided in each of said plates, an interlock system for controlling the alternating angular displacement of said locking rings, said system comprising a first latch pin cooperating with one of said assemblies, a second latch pin cooperating with the other of said assemblies, means for interconnecting said latch pins in out-of-phase relationship with the respective structures with which said pins cooperate to alternately latch one of said structures when the other unlatched structure is in a rotatable condition, and means for reciprocatively moving said pins in unison.

7. In an intermediate air lock interconnecting an exterior atmosphere and an interior atmosphere separated by a partition wall which comprises a tubular chamber penetrating said partition wall, the respective ends of said chamber being enclosed by an exterior pressure door assembly and an interior pressure door assembly, said assembly including a door hinged to said chamber, a locking ring encompassing said door and rotatably mounted on the opposed ends on said tubular chamber, each of said locking rings having spaced cam surfaces constructed to rotatably engage corresponding cam surfaces on said door to provide a fluid-tight seal between said door and said chamber and having a latch plate mounted thereon with a latch aperture provided in each of said plates, an interlock system for controlling the alternating angular displacement of said locking rings, said system comprising an interlock latch mechanism mounted on said tubular chamber and including a first latch pin cooperating with one of said locking rings, a second reciprocating latch pin journalled on said tubular chamber and cooperating with the other of said locking rings, a pair of fixed latch brackets mounted on said tubular chamber, each bracket being provided with an aperture and cooperating with a door assembly, the aperture on one bracket being aligned with the longitudinal axis of said first pin, and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, means for interconnecting said latch pins in out-of-phase relationship with the respective locking rings with which said pins cooperate to alternately latch one of said locking rings when the other unlatched locking ring is in a rotatable condition, and means for reciprocatively moving said pins in unison.

8. In an intermediate air lock interconnecting an exterior atmosphere and an interior atmosphere separated by a partition wall which comprises a tubular chamber penetrating said partition wall, the respective ends of said chamber being enclosed by an exterior pressure door assembly and an interior pressure door assembly, said assembly including a door hinged to said chamber, a locking ring encompassing said door and rotatably mounted on the opposed ends on said tubular chamber, each of said locking rings having spaced cam surfaces constructed to rotatably engage corresponding cam surfaces on said door to provide a fluid-tight seal between said door and said chamber and having a latch plate mounted thereon with a latch aperture provided in each of said plates, an interlock system for controlling the alternating angular displacement of said locking rings, said system comprising an interlock latch mechanism mounted on said tubular chamber and including a first reciprocating latch pin journalled on said tubular chamber cooperating with one of said locking rings, a second reciprocating latch pin journalled on said tubular chamber cooperating with the other of said locking rings, a pair of fixed latch brackets mounted on said tubular chamber and spaced therefrom, each bracket being provided with an aperture, the aperture on one bracket being aligned with the longitudinal axis of said first pin and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, the apertures on said latch plates being adapted to be rotated in alignment with the longitudinal axes of said pins, means for interconnecting said latch pins in out-of-phase relationship with the respective apertures in said bracket and latch plate with which said pins cooperate to alternately latch one of said locking rings when the other unlatched locking ring is in a rotatable condition, and means for reciprocatively moving said pins in unison.

9. In an intermediate air lock in accordance with claim 8 an interlock system in which said latch plate is rotatable into a position between said tubular chamber and said bracket.

10. In an intermediate airlock interconnecting an exterior atmosphere and an interior atmosphere separated by a partition Wall which comprises a tubular chamber penetrating said partition wall, the respective ends of said chamber being enclosed by an exterior pressure door assembly and an interior pressure door assembly, said assembly including a door hinged to said chamber, a locking ring encompassing said door and rotatably mounted on the opposed ends on said tubular chamber, each of said locking rings having spaced cam surfaces constructed to rotatably engage corresponding cam surfaces on said door to provide a fluid-tight seal between said door and said chamber and having a latch plate mounted thereon with a latch aperture provided in each of said plates, an interlock systems for controlling the alternating angular displacement of said locking rings, said system comprising an interlock latch mechanism mounted on said tubular chamber and including a first reciprocating latch pin journalled on said tubular chamber cooperating with one of said locking rings, a second reciprocating latch pin journalled on said tubular chamber cooperating with the other of said locking rings, a pair of fixed latch brackets mounted on said tubular chamber and spaced therefrom,

each bracket being provided with an aperture, the aperture on one bracket being aligned with the longitudinal axis of said first pin and the aperture on the other bracket being aligned with the longitudinal axis of said second pin, the apertures on said latch plates being adapted to be rotated in alignment with the longitudinal axes of said pins, means for interconnecting said latch pins in out-ofphase relationship with the respective apertures in said bracket and latch plate with which said pins cooperate to alternately latch one of said locking rings when the other unlatched locking ring is in a rotatable condition, means for reciprocatively moving said pins in unison comprising a rack mounted on each of said latch pins, a pinion gear journalled on said tubular chamber engaging each of said racks, and a lever means for rotating said pinion gears.

11. In an intermediate air lock in accordance with claim 10 an interlock system in which said means for interconnecting said latch pins in out-of-phase relationship co- Operates with said lever means.

References Cited in the file of this patent UNITED STATES PATENTS 1,178,775 Albright Apr. 11, 1916 2,830,838 Drager Apr. 15, 1952 2,926,012 Maher Feb. 23, 1960 3,032,835 Saar et al. May 8, 1962 

1. AN INTERLOCK SYSTEM FOR CONTROLLING THE ALTERNATING ANGULAR DISPLACEMENT OF A PAIR OF OPPOSED ROTATABLE DOORLOCKING MEANS HAVING A LATCH APERTURE PROVIDED IN EACH OF SAID LOCKING MEANS, SAID SYSTEM COMPRISING A FRAMEWORK, AN INTERLOCK LATCH MECHANISM MOUNTED ON SAID FRAMEWORK, AND INCLUDING A FIRST LATCH PIN COOPERATING WITH ONE OF SAID LOCKING MEANS, A SECOND RECIPROCATING LATCH PIN JOURNALLED ON SAID FRAMEWORK AND COOPERATING WITH THE OTHER OF SAID LOCKING MEANS, A PAIR OF FIXED LATCH BRACKETS MOUNTED ON SAID FRAMEWORK, EACH BRACKET BEING PROVIDED WITH AN APERTURE, THE APERTURE ON ONE BRACKET BEING ALIGNED WITH THE LONGITUDINAL AXIS OF SAID FIRST PIN AND THE APERTURE ON THE OTHER BRACKET BEING ALIGNED WITH THE LONGITUDINAL AXIS OF SAID SECOND PIN, MEANS FOR INTERCONNECTING SAID LATCH PINS IN OUT-OF-PHASE RELATIONSHIP WITH THE RESPECTIVE LOCKING MEANS WITH WHICH SAID PINS COOPERATE TO ALTERNATELY LATCH ONE OF SAID LOCKING MEANS WHEN THE OTHER UNLATCHED LOCKING MEANS IS IN A ROTATABLE CONDITION, AND MEANS FOR RECIPROCATIVELY MOVING SAID PINS IN UNISON. 